How do i remove the front drive shaft on a 97 ford expedition?

i been trying desperately to remove them tight bolts holding the drive shaft on. The joints where the tranfer case and shaft meet are nearly wiped out and the shaft flops around, vibrates and makes this awful noise. i have a Haynes manual but it says use a screw driver to keep the shaft from rotating. thats all good but the only problem is that i have an 4 in lift kit on and this makes it impossible for a screw driver to rest against the frame. i would find a good hold but then it will slip after a good tug. i considered turning the 4wd on so it wil lock the shaft in place. will this harm my if i do it that way? ALso do i need a torque wrench cause those bolts are incredibly tight, unless im turing the wrong way.