Desbloqueamos la puerta con la combinación.

It comes from the verb desbloquear, which means to unlock.

So desbloqueamos means we unlock or we unlocked, depending on context.

This form is a little tricky because for -ar verbs, the nosotros form in the present tense and the preterite can look exactly the same:

• desbloqueamos = we unlock
• desbloqueamos = we unlocked

You usually tell which one it is from the surrounding context, not from the verb form alone.

Spanish often leaves out subject pronouns because the verb ending already tells you who the subject is.

• desbloqueamos already tells you the subject is we
• so nosotros desbloqueamos is usually unnecessary

Including nosotros is possible, but it usually adds emphasis or contrast:

• Nosotros desbloqueamos la puerta, no ellos.
  We unlocked the door, not them.

Spanish uses articles like el, la, los, las more often than English does.

So where English might say we unlocked the door, Spanish naturally says desbloqueamos la puerta.

Leaving out la would sound incomplete in normal Spanish unless you were speaking in a very unusual or telegraphic style.

La puerta is the direct object of the verb. It is the thing that gets unlocked.

• desbloqueamos = we unlocked
• la puerta = the door

So the structure is:

• verb + direct object + prepositional phrase

That gives you:

• Desbloqueamos
  • la puerta
    • con la combinación

It means with the combination or using the combination.

Here, con shows the means or tool used to do something. In English, we often translate this as:

• with
• by using

So con la combinación tells you how the door was unlocked.

In this context, combinación usually means a combination code or number combination, like the code used to unlock something.

For example, it could refer to:

• a keypad code
• a lock combination
• a numeric access code

So even though combinación can mean combination in a general sense, here it most likely means the unlock code.

Because desbloquear means to unlock, while abrir means to open.

These are related, but not the same:

• desbloquear la puerta = unlock the door
• abrir la puerta = open the door

A door can be unlocked without being opened. So if the sentence specifically mentions the code or combination, desbloquear makes sense because it focuses on removing the lock.

Yes. Both are possible.

Because desbloqueamos can be either present or preterite, the sentence by itself is ambiguous:

• We unlock the door with the combination
• We unlocked the door with the combination

Context tells you which one is intended.

If you wanted to make the present more clearly ongoing, you might say:

• Estamos desbloqueando la puerta con la combinación.
  We are unlocking the door with the combination.

Because con is the normal Spanish preposition for expressing the instrument, means, or method used to do something.

Examples:

• Escribo con un lápiz. = I write with a pencil.
• Abrimos la caja con una llave. = We opened the box with a key.
• Desbloqueamos la puerta con la combinación. = We unlocked the door with the combination.

So con is exactly what you would expect here.

Yes, but it depends on what you want to replace.

For example:

• Desbloqueamos la puerta con ella.

Here, ella can mean it after a preposition, referring to la combinación.

Notice that after a preposition like con, Spanish does not use a direct object pronoun like la to mean it. Instead, it uses a prepositional pronoun:

• con ella = with it

So you can replace la combinación with ella after con.

Yes. Since la puerta is a feminine singular direct object, you can replace it with la:

• La desbloqueamos con la combinación.
  We unlocked it with the combination.

This is very common in Spanish. In fact, once the object is already known, Spanish often prefers the pronoun.

Because la puerta is not a person.

Spanish uses the personal a mainly before specific people, and sometimes pets or personified beings. But you do not use it before ordinary things like doors.

So:

• Vemos a María. = We see María.
• Desbloqueamos la puerta. = We unlocked the door.

No a is needed here.

Yes, this is a very natural word order:

• Desbloqueamos la puerta con la combinación.

It follows a common pattern:

• verb + object + extra information

You might hear other orders in certain contexts, but this version is clear and normal. For example, Spanish could move parts around for emphasis, but the original sentence is the most neutral and straightforward.

Yes, it sounds natural.

In Latin America, desbloquear is commonly used for unlocking things such as:

• phones
• devices
• doors
• systems
• locks

That said, depending on the exact situation, native speakers might also say:

• Abrimos la puerta con la combinación
• Desbloqueamos la cerradura con la combinación
• Desactivamos el seguro con la combinación

But the original sentence is perfectly understandable and natural.