Learn French: Nous voulons changer de travail.

When you have two verbs back-to-back in French, the first one is conjugated to match the subject, and the second one stays in its full, unconjugated form (the infinitive). Since voulons (want) is already conjugated to match nous (we), changer (to change) must stay in the infinitive.

Why do we need the word de after changer?

In French, the expression changer de is used when you are switching one thing for another of the same kind. To say things like "change jobs", "change trains", or "change clothes", you must use changer de followed directly by the noun.

The English translation says "jobs" (plural), so why is travail singular?

After the expression changer de, French usually uses a singular noun without an article (like le or un). Because you are giving up one job to get another single job, travail stays singular, even though it translates to "jobs" in English.

How would I change this sentence to say "I want to change jobs"?

The verb vouloir (to want) is very irregular. To say "I want", you use Je veux. The rest of the sentence stays exactly the same, because changer is still the second verb: Je veux changer de travail.