Depends on how handy you are. Have you ever tackled a job like this? You're basically gonna be taking apart your entire engine for this. I did this job with my father and his old 3.8 cougar. It took pretty much a weekend and alot of know how.
Difficulty wise it's not TOO bad, but you definitely need to know what you're doing. Consider having someone else do it with you if you haven't tackled anything this big.
2002 Mineral grey GT 5 speed. Flowmaster 40's catback, Mach 1 grille delete, timing advance, push button starter, Bullitt pedals, FR500 steering wheel, K&N FIPK, Self ported upper intake w/ spacer, Pioneer Avic D3, MGW shifter, MM FL subframe connectors, Mach 1 springs, Bilstein HD struts/springs