What Whopity said.
No refresher training is required for the re-issue of the licence, only for renewal of the SEP class rating and this may be done by a CRI, provided the amount of training is determined by the HT of a DTO or ATO. By the way, renewal is by proficiency check, not skill test.
Interestingly, while confirming this, I noticed that the Aircrew Regulation requires competent authorities to have replaced all JAR licences with Part-FCL licences by 8 April 2018 at the latest. I wonder if that's one of the myriad findings made against the UK CAA by EASA.