Then I wouldn't suggest hill training – if getting a PR on this 5K is your goal for the year.
I would be concerned that only doing intervals might lead to mental fatigue – mix it up with several types of speed work. But do not forget about a cutback week to allow for optimum recovery before pushing the paces for the following several weeks.
You need to cut about 30 seconds from your current 5K time to get a solid PR. That is 10 seconds per mile (give or take). I would increase the pace of your interval runs by about 5 seconds per mile in each of the next four months.
For example, your current interval pace is 7:00 minutes per mile, next month run them at 6:55s, third month at 6:50s, last month before the race 6:45s.