This is glycosylase-mediated base excision repair:
(1)Uracil glycosylase removes the Uracil, leaving an intact sugar-P DNA backbone.
(2)AP nuclease recognizes the AP DNA, nicks to both sides of the Apyrimidinic site
Nucleotide excision catalytic events then complete the repair: Helicase removes the short piece of the AP DNA, DNA Polymerase does repair synthesis, ligase joins the nick.