how to replace crankshaft seal??

[gloverfmx411]

pretty sure my seal is gone as its blowing alot of smoke and fouled 2 plugs today. been blowing alot of smoke last couple of rides. anyone got a quick "how to" of doing that?? yz 250 03mod also

Fiddy??
Nutty??

[gloverfmx411]

anyone????

[evil1]

only way of doing them is splitting the cases not that big of job