Nick,
You will get advice from others, perhaps someone has save the step-by-step, but it is really not that bad...just time consuming.
My advice, however, is that before you get started determine if the chrome bezel is in the shape you want. First you will need to prise the bezel from the instrument, using a small flat blade to gently uncrimp the lip that holds it to the rim of the speedo. Easy does it, patience, no problem. Now, if you have planned well, you will have already purchased a brand new chrome bezel from SLS (don't remember the cost, but I think around $25 and well worth it!) and when the glass is clean a clear you will have a shiny new bezel and bright lights to dazzle yourself!
Best,
g
'64 230sl, fully sorted out...ooops, spoke too soon