you sure can buy the parts and do it yourself. nothing complicated but it may take some patience to get the stock crankcase breather off. although i'd be curious as to why your fuel sender unit is leaking. that part runs about a $100 new last i remember.
if your crank case breather valve is leaking there's plenty of aftermarket ones available... i'd recommend the nichols breather because i've never seen a nichols breather leak... i've seen stm, stock, etc all leak. there goes another easy $100 for parts.