In reply to JonLongshanks:
I did the Rivington trail half last October without much training in about 1h50, pretty average but I had fun talked to people along the way.
Main mistake I made on the day was not listening for 'runners to the start line' so ended up right at the back which slowed me down having to amble behind the slower runners untill I could make a break.
Some stretching probably, do a bit of speed work, and make sure you are happy with your kit. You know you can do the distance so just work on injury prevention then you can push yourself a bit more on the day.