1
He is not going to change of job.
He is not going to change his job.
He is not going to change jobs.
When change is a verb, do not put of after it. To mean that someone is going to start a different job, use change jobs or change someone’s job.
Change of can be used when change is a noun: ‘The company announced a change of plan.’
2
We have made several changes of the house.
We have made several changes to the house.
Use changes to something for changes that somebody deliberately makes: ‘The school has made several changes to the timetable.’
3
There has been a change of the plans: we’ll leave earlier in the morning.
There has been a change in the plans: we’ll leave earlier in the morning.
A change in the plans means that one or more details in the plans are now different.
A change of plans, not a change of the plans, is a common expression meaning that the plans have changed. It often means that the original plans have been replaced by new ones: ‘There has been a change of plans: we are going to Rome instead of Venice.’