I have replaced the window rubber seals on my ABI Ace Herald which should be simiular to yours. First measure around each window to get lengh allowing a bit for waste. Purchase rubber and plastic filler strip frrom a caravan spares shop. Remove wndow arms. Remove plastic (grey) strip to expose staples securing rubber seal. Pull off seal. Fitting new seal is reverse of removal. Its very simple . Spare shop can also advise if above needs more detail
mike
October 2008