This techdoc gives steps on how to download CA 2E 8.7.3
Release : 8.7.3
Follow these steps
1. login to Broadcom Support web site
2. from left panel choose My Downloads and then double click on 2E
3. choose "Solutions" instead of the default "Products"
4. choose CA 2E 400 Toolkit OS/400 RISC then 8.7
5. then use either http or ftp to download "CA 2E R8.7.3 SOLUTION"
For other cumulative patch, the steps are very similar. For example, for 8.7.4, in step 5 it should be "CA 2E R8.7.4 SOLUTION".