all u need is a yoyo with hubstacks and a yoyo string
1-take out the string from the yoyo
http://img33.imageshack.us/img33/6670/img0150hb.jpg
2-place it under ur hubstacks as shown in the pictrue
http://img294.imageshack.us/img294/9928/img0151ff.jpg
3-pull it hard & thats all !!
http://img571.imageshack.us/img571/9853/img0152c.jpg
tip:make sure u don’t loose any thing while doing this
have fun 
http://img405.imageshack.us/img405/4273/img0153cj.jpg
if u like this dont for get to comment
cool
thats every thing i do but after it comes out the bearing is stuck in the hub
try oiling the bearning and placing the string again but this time just under the bearning without the white stick thingy
if it didnt work place 2 strings under the bearing (same way i showed in the pic) and call ur bro for help
u hold the yoyo and let him pull try doing that in some place clear so if the o-ring fell down u can see it
tip:if the o-ring is white try it on dark ground and if its black try it on white ground
can’t you just use something like an adjustable wrench though?
YYF can make you a custom bearing removal tool I think. They made some a while back. Pretty cool too.