Changing Dana 30 ujoints?

So next week I have put aside a day to change both my front ujoints. It pops in 4wd and the mechanic told me they were seizerd. A few questions first. I have a writeup on how to change them but still wondering how hard it is? Biggest job I have done is rear driveshaft. Do you have to pull the differential cover off? I'm just gonna pull the shafts and have a shop change the ujoints for $10 since I dont have a press, but will I need to change the seals to since there coming out? HP D30 of a 99 XJ