It's not quite the way to do it.. Far to many changes..
If you do as you suggested then you will end up in a pickle and not know what did or didn't work etc...
Have you done any fasting tests, this should be your first port of call, as you will be able to see at what part of the day you are struggling with.. It will also give you a better idea how best to split your insulin to start with..
When splitting your insulin, day one you should reduce the injection at night by what you intend to inject in the morning... So if you usually take 30u at night, and intend to split 25/5 then take the 25u in the night...
After the first split you need to monitor for a couple of days to get a true idea to how this actually effects your control.. Then review the data and work in one area alone, only make a adjustment to one of the injection following what your data you've collected in the past couple of days for best choice..
Then wait and monitor for a couple of days before reviewing and repeat as it may be that you require an uneven split, also if you can't quite pin it down you might need to start looking at the timing of the injections as this can sometimes make a difference..
When I was on MDI my split was 10u at 11pm and 6u at 11.30am gave me best control that I could achieve under MDI..