Most likely the knobs are a push fit, with a retaining nut underneath. Possibly cut more of the fascia away (another 'horizontal' cut a few mm lower) so you can get below the edge of the knobs and lever them off without visible damage?
@MrE started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
Most likely the knobs are a push fit, with a retaining nut underneath.
Possibly cut more of the fascia away (another 'horizontal' cut a few mm lower) so you can get below the edge of the knobs and lever them off without visible damage?