Ermmm...if its a fourtrack (or sporty for that matter) its slightly more involved than the previous post suggests...To replace both wheel bearings would take about 2-3 hours at a steady pace.

The hubs are indeed held on by 5 allen key bolts.But before you can get to them you have to remove the hub front cover held on by some small torx screws. The heads of these screws can be corroded or worn and then you have your first problem..I solved it by using a strong flat bladed screw driver driven an an acute angle to loosen off the screws (which were well corroded. You then undo the allen key bolts..easy enough. Remove free wheeling hub casing...you are now presented with a large nut...it will most likely be damaged at the edges from previous attempts to get it off without the use of a dedicated hub nut box spanner.Either get thee a dedicated wrench or add to the damage using the aforementioned flat bladed screw driver and hammer to remove.Behind this is a locking washer..bend back edges of washer to enable it to turn..remove...then you have the second large hub nut...remove in same manner as the first..behind this is the outer bearing..prise gently out with 2 screwdrivers..one either side...out she pops...if you want to remove the outer bearing race then I suggest you remove the whole assembly which necessitates removal of the brake caliper and brake disc...if you are simply wanting to replace the outer bearing then you are almost done...replace old bearing with new...reassemble in reverse order..job done...but it will have taken you an hour or more if things went well..you still have side 2 to do...good luck m8