That will work, or U can just do it by moving the auto gear one click back and forth. However neither method will fix reverse. There are two ways to fix the tranny properly. One is to go to the settings screen, and to "Change Parts". Go to the tranny and try to remove the race tranny, and re install it. In the case of the Stratos WRC, it won't actually allow U to remove and replace it, cuz the race tranny is the only option, however, going thru the motions will correct all gear values including reverse. The other way to fix it is to edit the ini file. U can change the values for the following lines so that they read like this.
240=-2999
244=-3284
248=-2147
252=-1541
256=-1162
260=-921
264=-767
268=-64538
272=-4101
276=-37