Conversion of 2WD to 4WD

How much trouble would it be to take a 2WD truck (my 1996 F150 300 auto XL std cab) into a 4wd? Hypothetically, of course, but I'm just wondering.

To start off with ,its very time consuming even for a very experienced fabicator. I assume you are a fabricator with all access to tooling needed?
Anyway you have to basically start from scratch on the frame in front, decide if you will be doing a straight axle conversion or a newer independent type front? then buy all parts needed (costly) then you have to make all mounts needed or at least weld new brackets to frame for suspension. and we have not even started on tans. case mounts and tranny change to accomodate this set-up (also costly).
to be honest you would be far better off buying a donor 4x4 frame or complete rolling running gear with all parts already there and in correct drive angles and such.just swap your truck body onto . it,s much faster and alot cheaper than your asked about route.
just my $.02 worth

Nevermind.

thanks for the input, though, wow, That's a lot of work.

it would be esaier to use a 79 ford front end and springs.