SRIV root (Installation Directory) is usually located at "C:\Program Files (x86)\Steam\steamapps\common\Saints Row IV".
BTW, I also have a mod that skips The Real World mission. This is made for last version of SRIV and most likely works better than other older counterparts.
To install, just place the included "patch_compressed.vpp_pc" to "C:\Program Files (x86)\Steam\steamapps\common\Saints Row IV\packfiles\pc\cache".