Mt Ritter is a long climb, but it is worth the effort. Start out by establishing camp at Ediza Lake prior to your ascent. The SE Glacier route (first ascent by John Muir) follows the path of least resistance up the SE side of Mt Ritter.

The route first gains a broad bench below Ritter and Banner Pk., then climbs through a band of cliffs, then over ledges and ramps before arriving at the edge of the SE Glacier. By now hours have passed, you are very tired and there is still a long way to go. You now ascend a long, loose rock gully to a talus slope, cross the talus slope to the ridge, follow the ridge to the summit.

So, now that you have a rough idea of what the route entails, if you're still interested, you need to visit for more detailed info.

Do your research, be safe, have fun, bag a summit.