Are you cool with riding through downtown St Paul? If so, keep going on Marshall all the way to Kellog. Looks like there's a slight jog in there to get around St Paul Tech College, but keep going east until you hit downtown. You'll be up on the hill by the cathedral & have to get down to downtown, Kellog is a main road that'll eventually intersect 7th street. Thats the giant mess in front of the Excel center. But you'll want to get yourself on 7th Street. It'll take you all the way through downtown over to Metro State.
If you're open to a longer route (when the weather improves), cruise down to the bike trails along shepherd road. You can bypass a lot of downtown St Paul & traffic this way, plus mostly stay off streets. You also might consider using Summit Ave instead of Marshall, since Summit has the bike lanes. Actually, Summit might be easier altogether. At the east end of Summit, watch for Ramsey St. Basically Summit starts to curve North & Ramsey takes you down a big-ass hill to downtown. 7th Street is 2 blocks past the bottom of the hill. Might want to find a different hill for the route home though.