It will depend on how handy you are with the fiddly bits.
Dropping the old axle will be pretty easy - lower shock mounts & u-bolts get plenty of penetrating oil on the u-bolts a few days before you start. Probably worth getting new u-bolts too.
Its the brakes which might take the time. Unless its in good nick (ie replaced recently) expect to have to renew the couplings for the flex hose connecting the hard line on the chassis to the t-joint on the axle. You'll also need to disconnect the handbrake cables which I think will mean you need to strip the drums & shoes out - old axle and new.
You'll obviously need to bleed the brakes too.
Make sure you're matching the R&P ratio on the new axle to what you've already got. 4.0's usually have 3.55:1 but the 4 banger and diesel will be different.
Stu.
