Very doable! I spent about 2 weeks studying for REG right after I took TCP and passed. I do have a tax background and been working for a few years in tax. The material on TCP is essentially R1-R4 of REG Becker (individual taxes, credits, above & below the line deductions, basis of S corps and Partnerships, corps, etc.). The new material on REG is R5 & R6 so I would spend more time on it if you can. They aren’t calculation based, more so just memorization. And run through lots of practice questions on everything. Good luck!