You cannot move the seat manually. The contacts within the seat controller switch must be dirty. To fix properly, you must either disassemble, clean and reinstall your current switch (about $100 for the part if memory serves, and about 10 minutes labor) or replace it.
Howewver, try this; spray a little WD40 into the holes in the front of the switch. This tactic got mine working, and it stayed alive for nearlt a year (at which point I went the replacement route).
All the best, Michael