Internal ssd upgrade on my Mac Studio (M2 max)

I can give you completely reliable advice.

YOU CAN'T.

if you need more storage, and you insist on INTERNAL storage ONLY, the way you upgrade is by selling your Mac, and using the Cash to buy a Mac that better meets your needs.

if you might consider some fairly portable solutions, look at things like this:

and this:

about actual size, 1/4 in thick.

there are MANY more.

Two easy choices:

Off load your large directories like Music, Photos, Pictures to an external drive

or make a clone of your internal drive to a larger external and use that as your primary boot drive.

try some self-powered drives, they are FAR more reliable.