Ahh okay, sorry I thought the squat challenge was everyday - must've misinterpreted the 30 day part of it. But yeah obviously feel free to change bits around and integrate the squat challenge in with the programme in the form of rest days etc.
If you are going to move things around though I'd say make sure you have 3-4 sessions of long distance running, and 1-2 sessions of Interval training (if you want to do it).
Interval training is where you sprint over a short distance repeatedly (e.g. 20 metres), whilst having short recovery time between runs (e.g. 1 minute). Normally you do about 10 runs with one distance.
Then you can either decrease the recovery time between runs (down from 1 minute to 30 seconds) or keep the recovery time the same but increase the distance (from 20 metres to 30 metres) although the former is normally preferred. After this it's just a matter of fact of rinse and repeat.
But if you're still not sure, do a google search. If you're still not sure after that, just stick with the long distance running