hiiii,
Following are the steps to find the enhancement related to Packages,
1) go to se93 and enter the tcode where u want to make a enhancement and click on display. Copy the
Package name of the that transaction code
2) Enter the SMOD tcode and then in Menu
utilities--->Find
Enter package name and Execute(F8)
all the exit name related to that packages are displayed and on the basis of exit description make sure that the exit name is required for your requirement or fulfill the requirement
and finally copy the exit name
3) Enter the tcode CMOD and make project name with Z or Y and hit the create button and then click on Enhancement assignment and enter exit name which is copied and implement it