Assuming it's a bolt on neck it shouldn't be difficult at all
The older Japanese Charvels all featured trems that were above the surface of the guuitar rendering the strings at tunamatic like heights rather than the lower Fender like profile
Interestingly enough this used to cause Vai problems andf that is why he used to have a piece of plastic/foam stuck to the front of his Jacksons when he was using them to raise his arm up to a more strat like angle with respect to the strongs
What will be required is an overhead router or milling machine to make the neck pocket parallel to the face of the guitar (A router used on the face of the guitar would work equally well).
A strat like height can then be achieved and a careful up-pull rout machined under where the trem sits created
The bridge pivot posts will need to be removed, drilled deeper and set in so that they are flush with the recess routing
It is a task that I have done a million times having worked on so many Floyd equipped guitars
I did it to my old 1986 charvel - seen below
