Fitting frsky xht module into a futaba 6M 35mhz ( circa 1982)

[2435mick]

Ok, first post and help needed, I'm a dab hand with a soldering iron so thought I would fit an frsky xht module into my old but much loved futaba M 6 channel tx, alas, I'm not that good on establishing which is the ppm signal I need to connect to on the tx ( there is no trainer port) and also, apart from removing the crystal and antenna is there anything else that needs to be disconnected, cheers for any assistance