Java .Class file change string

Question

I\'m trying to modify a minecraft mod (gravisuite) that puts \"Gravitation Engine OFF/ON\" whenever I press F, however I want to change this string, I started with replacing

Answer 1

There are checksums for the files:

Archive:  dvt-utils.jar
Length   Method    Size  Ratio   Date   Time   CRC-32    Name
--------  ------  ------- -----   ----   ----   ------    ----
332  Defl:N      226  32%  11.05.31 19:41  a745ad09  META-INF/MANIFEST.MF