I opened GameplayData.package in S3PE now which resource name is it in?? I have spent a long time looking for whatever it is that I'm trying to look for.

Im trying to mod the career performance to make it easier

I've looked in the XMLs dealing with careers and work and I can't find it. I have seen a way you can 'cheat' to get what you want though. If you look at the one called WorkHardTone, this deals with the Work Hard which you can select while at work, as opposed to sucking up to the boss or one of the other selections. It has this:

<kPerformanceModifier value="3" />
<kWorkHardStressPerSimHour value="-10">
<!--This value is additive. It will be combined with the regular job's stress level-->
</kWorkHardStressPerSimHour>

The performance value 3 gives you 3 times the performance as in that normal work tone. Put this at 8 or 10 or so and you're probably guaranteed a promotion every day. The stress per hour is what makes your fun decrease much more than in the normal work tone. Put this at 0 if you have to, to keep your sims from losing so much mood that they quit the Work Hard tone by themselves.

It wouldn't be these values in the Careers XML, would it?

MaxPerfFlow
MinPerfFlow
MaxPerfFlowMaxLevel
MinPerfFlowMaxLevel
and FunStressPerHour

AwesomeMod may help here too. There is a configurable multiplier named JobDifficultyScaling. The online config tool doesn't let you set it below 1.0, but if you edit the XML directly in aweconf.package you can set it below 1.0 and have easier jobs without having to edit the performance values for every different career.