Gidday

I'm looking to replace my crank seal on my Yamaha XV 250. It doesn't say on the rego sticker but i'm sure it's a virago. I've had the alternator out already cos that was giving me trouble, so i'm sure i'll be able to go further and fix it. I don't have much bike knowledge but i'm a car mechanic and am real keen to learn about bikes.
Any Adivise would be awesome.

Thanks