Can a probated will be changed?

No. A Will is probated after death. Dead people cannot execute legal documents.

Can a probated will be changed?

As JudyKayTee said, no. Of course not.

But I am wondering, as the answer is so obvious, whether OP meant something else.

For example:

If the will was admitted to probate, and it's later discovered that the testator wrote a later will, it is possible to ask that the later will be admitted in substitution for the earlier will.

Is the word you want 'contest'?

And a will can be contested while it is in probate, but once it is final and one, normally it can not be contested.