You should be fine.....I replaced mine in about two hours for all four.......Spray some WD 40 or PB Blaster some sort of penetrating oil on the bolts about 24-48 hours prior to the removal that should help out with loosening.
Rears are just unbolt/and bolt. Start at top first that should give you more room to work the lower bolt and flexibility.
Fronts: I find mine easier with tires removed...it gives you more leverage for the upper nut. If not removed then turn tires full left for driver side and full right for passengers side.
Wrap a cloth around a set of good pliers and hold the strut while loosening the nut. This should protect the strut from getting gauged. Not as critical on the shock coming off but definitely critical on the new strut. After the strut is installed don't forget to slide the dust boot around the collar to keep debris/dirt/grease off the strut.
If they arent Bilstein's then return for Bilstein HD'S and start process over again....LOL!!!