I managed to splash diesel all over my tan leather boots this morning. How can I get the stains out? I've asked a few mechanics who aren't too positive I can. I'm reluctant to try anything without a recommendation in case I wreck them.
Try asking the oldest boot repair person you can find. There's a good chance you have already "wrecked" your boots as far as the colour and finish. You may have to settle for a slightly different colour than you had originally due to the small variety of after-market shoe polish colours
From what little leather working I've had, the colour can be removed with alcohol and new polish with the colour you wish is worked back into the leather. It's a work intensive procedure done a square inch at a time with a small soft rag gently in a circular motion both for the removal and reapplication of the polish. An agreeable repair person will show you how if you want to do it yourself. It's not hard but it needs patience because it's time consuming after the leather is stitched to the last.
In addition to polish, there are leather dyes, both semi-transparent and opaque that can cover your original. Depending on the finish, you might find something that suits you.
I'm sure you'll get more results than with a mechanic where it happened.