How this might look in practise?
Research shows that you the optimal point for muscle growth is to train each muscle 2-3 times per week. Rather than grouping all the training for a body part on one day spreading it out over several sessions makes it easier to recover from and can allow a better quality of training in each session as the muscle is less fatigued.
So, your training could be arranged something like this:
2 Upper/ 2 Lower Days (4 sessions hitting each muscle group 2 times)
3 Full Body Days (3 sessions hitting each muscle group 3 times)
1 Upper/ 1 Lower/ 1 Full Body Day (3 sessions hitting each muscle group 2 times)
These are just some suggestions you will need to play around to find what is most optimal for you.
Now to how you train within those sessions.
There has been a lot of research on the optimal amount of training a muscle needs to stimulate growth. There can be some variation between different people and within different muscles but around 40-70 reps per session has emerged as being what best achieved this.
So, a good baseline would be to keep mostly within the 6-12 rep range this allows for a heavy enough weight to be used that we are creating mechanical tension but that we are not training with so high an intensity that we cannot get to the optimal amount of reps. This is not to say all your training must be exactly within this you could do some lower rep higher intensity work on things like squats or deadlifts and some higher reps on accessory movements later in the session to train more for a pump (metabolic stress), but generally this range will be ideal for signalling the body to retain those muscles.
In the session itself it should be obvious that your big compound movements (squats, bench, deadlifts, overheads) should come at the start as they give the most bang for your buck since use the most musculature also they will be creating the most mechanical tension, therefore these should be prioritised. I would pick 3-4 of these to focus on and keep them throughout the entire diet. Your accessory/ isolation exercises can be changed every month or two to keep training fresh and to take advantage of muscle damage.
This should give you a good idea of what you should include in your training plan to optimise your bodies response to your diet and hold onto those hard earned muscles so that when you lose the fat you not only look lean but jacked!
These principles are similar to those recommended by Coach Mark in his article What’s the Best Way to Tone Up?
So, you may want to have a look at that for some further reading.
But before you even begin to implement any training strategy, you need to have your head in the right place in order to proceed in a manor that will be successful.