95 Toyota Pickup SR5 with 3VZE motor. #4 exhaust lifter is turned so I cannot access the gap to pry out the shim. There is currently 0 clearance between the calm lobe and the shim. need to pull the shim in order to get a micrometer measurement so I can get a thinner shim to install

 

This is a very handy tool. Makes changing valve shims painless.

 

The lifter buckets are free floating and should be able to be turned fairly easily.

Is that an exhaust valve??? If so it is likely burned and restoring clearance will not make it pressure tight again. Only valve grinding will do that.

Once in a while you'll get lucky though. I wish that luck to you.

 

You cannot pry out the shim (unless you have enormous clearance!) without the tool like the one amamike 91 shows. That tool depresses the lifter bucket so that you can hold it down with the accompanying t-shaped tool. In my experience, I still need to get to the gap to insert my tiny screwdriver to get the shim moving up. You might be able to pull the shim up out of the bucket with a really strong magnet. You can't rotate the bucket when held down (too much force), so you usually rotate the bucket before using the red-handled tool. And if you really have zero clearance, the shim may be pressed tightly enough against the cam lobe that the bucket won't turn.

Is that your circumstance?