How easy is it to view the offending resisters?

Im thinking of selling my 5k's and don't want to do so without checking the condition of the resisters and replacing/discounting if necessary - would rather someone else did any replacement but looks like in UK options to repair legacy kit is getting limited.

Before I purchased these, the person that I purchased from said that they were serviced by a dealer so hoping that they are all good.

Meridian owner since 1992
Prime & PSU, Focal Elear headphones, Roon (ROCK 8Gi5 NUC), Explorer 1 & 2, F80. 200/203, various Sonos (via Roon).