I agree -- practice SLOWLY. A metronome, set to a ridiculously slow tempo, is a great idea. Practicing up to tempo and then slowing down or stopping to change chords, even just a few chords per song, will be counterproductive and could create bad habits.
I sit with my 'uke while I watch TV with my husband and practice chord changes over and over (without strumming, of course). For very tricky chord transitions, I will practice the same one over and over. And over. And over. Really, really slooooooowly. I'm sure it would be very annoying to anyone, but I never let anyone hear.
It does work.
And yes, I'm a big fan of Uncle Rod. His idea of "boot camp" is not very military; you can work on as much of it as you want at one time. As someone posted earlier, I used to use it as a warmup. I still do sometimes. It is not necessary to learn all the chords. Uncle Rod suggests saying the name of the chord each time you change to it, either aloud or just to yourself, to help connect the name to the action, and I find that helpful.
It will get easier! If you find yourself getting bored or frustrated stop with the drills and play something you feel like playing and have some fun. The 'ukulele should never be scary! Well, almost never.