No problem at all. It is an easy repair and the parts are available from Amazon or most any RV supply store. for about $10 Remove the screws that hold the rim in place and you will be able to pull it out to see it and replace it. What you need is:
That trailer has been out in the sun and weather judging from how much the plastic is deteriorated. If you have not already, get on the roof and check the tank vents and anything else plastic up there.