Tikkas are amazing actions. Of course you want to upgrade it and of course you want to do it yourself. This should provide some help to those attempting the herculean task of removing their factory barrel from their Tikka action.
Please Note: I'm no expert -- just a dude trying to figure out the best way to do this and documenting it for the benefit of others. Hope it helps.
Notes:
-Many have suggested using rosin or drywall paper to wrap the barrel in the vise. Apparently that works much better than an index card.
-The Wheeler action wrench is a #1 (not 2).