"A" frame cover replacement

Having tried to move my caravan with the motor mover and with the van wound down to low on the jockey wheel, I went and caught the "A" frame with the jockey wheel and cracked it quite badly. After much waiting I have managed to get hold of a replacement cover and I just wondered if any member had experience of changing these covers and just what is involved. Before I start are there any pitfalls I am likely to fall into, or is it just a straight forward job. Many thanks in advance for anyone who may be able to help.