Years ago, I bought an "Injector Puller" set, which is a nice HD plastic box with many adapters for various brands of diesel fuel
Sorry, "Old Timers" must be setting in, or maybe just CRS, after all I will celebrate 80 years in July.
My shop is full of Harbor Freight tools, so check their website. This kit has a "U" shaped device that straddles the injector, a screw attachment that goes into the common return line fitting. Then you attach it to the threaded rod and out she comes. However on some I have had to use a slide hammer.
BTW, I have two Perkins
4.154's available that need to be rebuilt or can be parted out. Pensacola