The two seals are pretty easy to replace; the shift shaft seal can be pried out with a small pick or screwdriver (just don't gouge the mounting area), you'll hafta pull off the stator cover, shift lever, and left footpeg. For the kickstarter seal you should be able to just remove the kicker from the shaft and pull the seal. Once you get them off you should be able to find them at a bearing store, the National part number for the shift shaft seal is 10x22x7 and the kickstarter is 20x30x5; those are also the metric dimensions for IDxODxCC. If you don't get OEM make sure they are rubberized (not just bare metal on the outside or mounting area), and if possible get a double lip seal.
BTW have you changed to a different type of oil? My shift shaft leaked like crazy the first time I changed the oil, using 30W like the manual said. After that I've stuck with 80W90 and never had any leaks. Just curious, if you changed oils and the new stuff has more detergent or additives you might be doing the countershaft and even right crank seal soon...