It was my plan...
I had a plan to do just this but a better offer came along so didn't do it. However....
Assuming you have a valid ATPL(H) with valid IR you'd need to do the following:
A. Do 5 exams (PoF, instrumentation, AGK, Perf and Op Procedures)
B. Get a PPL(A) and hours build to 100 hrs PIC (also grab a night rating in there - 5 hrs)
C. Get an MEP (5 hrs), ME IR (10 hrs because of heli IR), and CPL (15 hrs)
D. You'll have MCC credit so then it depends on the job offered.
This is all assuming you want to go the fully modular route as I assume you'll keep working the current job. There are integrated ways to do the same. All this is in CAP804 of course.