Intervals mate! thats the answer. You have some time to play with which is good, you need to have a scan of Gresham's guide over at
PlanetFear that will fill you re what to actually do to perform intervals, and I would say try and work towards some kind of macrocyclical routine, i.e within the week mix it up and work on a macro cycle until you go, again, Neil 'bigger biceps than my own head' Gresham is a good source of this info.
Mix it up, remember resting is the most important part of any training and write it all down.