Cant get aerial to fit into base because of this little thing

[Carl_1290]

Hi there, i need some help guys :001_unsure: some twit before me had put a silly chrome aerial on and i had to get the pliers and heat on it to remove it as it was solid as a rock because of a rusty screw thread. I however have a new genuine renault aerial complete with new screw BUT i cant get it to fit in as some little bit (aerial screw base) is lose and wont stay in position so aerial just falls out of the base on the roof





Can anyone help me please?

Thanks

Carl