Hey Guys, First I'd like to thank all those, who are obviously more gifted than I am in this filed, for their dedication and work on presenting us all with a road map to bring our "outdated"(?) machines into the "Now". I'm a noob but learning more each hour, so bear with me. I've started reading all the post before I jumped in and attempted to install El Capitan on my MP 1,1 which is still running Lion. So, I followed the steps using a 2015 MBP, firewire to Thunderbolt, etc., and got El Capitan loaded on the MP's drive, but the problem I'm having is replacing the boot.efi's. 1.) When I down load Piker's efi it comes in as boot-2.efi, is that correct? 2.) When I try to replace the original efi with Piker's efi, by dragging, I get the circle with the diagonal line through it, i.e. NO BUENO. 3.) When I try removing the original efi I get the message: “boot.efi” can’t be modified or deleted because it’s required by OS X. Reading through the post it seems fairly straight forward and comprehensible, but I'm stuck on stupid I guess. Any clarification and/or direction is greatly appreciated.