You'll need a press to get those out or a cobbled puller using a threaded rod and washers and sockets. I wouldn't replace those unless they're visibly damaged/worn.

BTW...I just finished putting in my Bilstein strut inserts. Make damn sure you get the gland nut (the BF nut that comes with the Bilstein inserts) tight and the insert bottomed. I had trouble on the passenger side getting them tight enough....the driver's side was a snap. Make sure you lubricate the gland nut threads in the strut with antiseize past. One, so you can get the gland nut in there far enough, and two, so the next poor sod can get it out without 600ft-lbs of torque.

I used twp pipe wrenches and four foot cheater bars.

I also have a torquemeister gland nut wrench on order from IPD. For the next time I have to fool with bilstein struts.