Louis GL

Hi all, I have bought a Zen Blue+ Decoder and a small stay alive from DCC Concepts for my Bachmann 64xx. I have fitted the decoder to the loco with ease, but i'm finding it hard to find space for the PCB board for the stay alive as it's a plug and play version. Removing the body shell of the 64xx is easy, but there are three other screws below the footplate / coal bunker, I have removed these too, which seems to loosen the coal, but it won't budge and I don't want to force it. Does anyone have any suggestions as to where I could slot this control PCB and stay alive please? I have seen a few people remove the weights from Panniers, but this is on the 57xx version, not the 64xx.