You politely ask someone to help out if you really cant persuade anyone to come with you.
Or, you remove your own saddle and rub your gloved hands over the pony, ask the ring steward to assist when getting back on if needed.
I'd try and find someone to go with you or meet there, at that level. They don't need to be horsey, just tidy and able to bring your little bag into the ring. You then get them to hold pony while you remove saddle and tidy up. Then they hold pony again while you replace saddle.
Is this the pony you previously mentioned that has been to HOYS twice? If so, prep well, and definitely take a person with you.
You could ask someone at the ringside if they can help.
Or the steward will help to some extent. A few times I had no help and just enlisted the steward to put my saddle on the ground behind the horse . Plus points for having a pony you can do this with but obvious downside is you can only have what fits in your pockets, grooming utensils wise ie next to nothing.
Best thing, pounce on a likely suspect outside the ring. Lots usually willing to help.
Ask a few people who are with others in the ring if one of them minded giving you a quick hand if they are near you in the line up. I can guarantee not one person will decline. You will be fine!
I’m often on my own so I take a few baby wipes in with me and wipe him over with my glove and those. Someone always offers to help whilst putting saddle back on even if on occasion it’s the steward and then it’s hunt someone with steps to get back on. The judge can see past the fact he’s not been brushed off and it’s not going to be the thing that wins or loses the class. Good luck and enjoy