Re-grouting of Shower area - recommendations wanted please

Hello,

I had my shower re-grouted about 4 years ago but I can see that the grout is deteriorating and some small cracks are appearing which are likely allowing water to seep through. It needs the old grout taken out, without damaging the tiles, and then replaced. Has anyone used anyone they can recommend for this? Likely just the lower half of the shower but happy to take advice from whoever does the work.

Thank you!