I'm teaching the new OCR spec for the first time this year too and thought the same about the studies - criminal behaviour study 1 in particular as you mentioned is far too detailed!
I've condensed each study down onto one sheet of A4 (an "information sheet") and will be giving these to the students when we do the studies. I won't be giving them the textbook for this part of each topic as I don't want them to be daunted by the volume of information!
In terms of teaching the studies I'm using the same techniques as for the previous spec. Combinations of; teacher delivery, question and answer, storyboards, some "active" tasks using play-doh and role play etc. etc.
Looking at the example assessment materials, the exam board seem to be favouring short answer questions so I'm going to ensure students know every detail necessary using regular quizzes and games (mostly as starters and plenaries) rather than practicing longer answers as much as I used to (for the old 10 markers).