Throw it in the washer (warm, medium agitation), then toss it in the drier (perm press). No bleach. The 01 tag you cut off actually says these washing instructions.
Here's a time comparison...
1. go buy new cover - 5min
2. put new cover on frame - 5min
total a - 10min
or....
1. use one method of stain removal - 5min
2. wash -30min
3. air dry - 120 min
4. try second method of stain removal - 5min
5. wash (again) - 30min
6. air dry (again) - 120min
7. go buy a new one - 5min
8. put new cover on frame - 5min
total b - 330min
Difference between total b and total a - 320min
Other things you could do in that time
1. drink beer
2. study
3. goof off
4. work out
5. sleep
6. watch several movies
7. any combination of the above.
And this is the point where you get to put a cash value on how valuable your time is.