Calculating EV of strategy changes between games.

I swear I've read how to calculate the EV difference for individual strategy changes between games (either in a book or a column) but I cannot remember where. For example, if you use 9/6 JOB strategy on 8/5 BP, you can only achieve 99.16 instead of 99.17...what is the way to calculate what the strategy changes that make up the extra .01 in EV are worth? Another example would be JOB vs 10/7 DB and how much does holding AAA out of AAA55 account for, in the ~.54 difference between 99.63 and 100.17?

How do you calculate the incremental EV (either with software or by hand)?