compare ax 2012 ssrs reports

How to compare ssrs reports in AX 2012

this is the senario..

There is a VAR layer change to a ssrs report, then there is a hotfix (FPK layer change) which has to  be merged.

The compare tool runs out of memory as well as next to useless.   It would be nice to see that the FPK layer change is as well as what the VAR layer was???

Any suggestions?

Thanks

Tony