First off you need to find a fun program that you've done before. Something that involves your legs and arms at different points, maybe with a bit of running or something in there too. E.g.
Run 50m fast
Then what you need to do is think of single leg variations of each exercise. Yes, single leg! On the example above it could look like this:
Single leg shoulder press
Single leg squats
Single leg press ups
Single leg jumping lunges (start on one leg, jump into the lunge on the other leg, jump back onto the original)
Hop 50m fast
It might sound a little silly or even pointless to some but believe us it'll work you harder and give you different benefits from previous workouts. This one will really hit your lower body joints, proprioception, balance, coordination and also your core.
Give it a go and see how you feel. Chances are you won't be able to do the same weights / reps you do on 2 legs when you're on 1 leg. Don't worry about that, it's to be expected! If you're unsure what single leg variations look like then get in touch or have a look online - try YouTube.
Hope you enjoy it!