I need some training advice ASAP .

[Ikabob]

I have a 5K race coming up that involves about 5 hills, one is steep (for me). I have been doing cardios and some minor infrequent lifting. I am older but not in bad shape but I find that my legs are tired easier....I need to strengthen them, I can tell...all the indoor working out has helped my cardio but the legs....not so much. I went to the race location yesterday and did the big hill 5 times as fast as I could....it was difficult and my legs were wiped out after...I walked and jogged a little back to the car(about 1.25Miles). OK....question...today is April 13th, the race is May 7th....How can I <b>strengthen</b> my legs and continue to increase my cardio without overtraining? I want to peak on May 7th. Can I do a lot of leg strengthening exercises now? When should I taper and stop the lifting? Any suggestions are appreciated. Thank you! Ron