[ADD] In addition to the Museum Environment you will need to purchase Ivan Tojakov from the PSN store. (currently $0.99 US)
The Normal mode of this is relatively easy and the Hard mode is doable but I discovered the following link which shows by far the best way (and which launcher to launch from) for each combination on Painful.
Spank the Monkey Painful Playlist
One thing to note is that on Museum you cannot get the infinite time bonuses like in Downtown and they are limited to 30 seconds max (40 if it is a clean run with max bonus) so making sure that you keep getting the 30 second bonuses is essential to getting 60 monkeys. If you miss one or two combos it is not the end of the world, but I ended up doing the entire list from 30-50 with under 30 seconds on the clock because I missed some around 20-30.