Rounded Grub Screws Removal

As title suggests. Picked up a free frame a few weeks ago and the seat post is held in place with 2 grub screws that have had the socket rounded off and I would guess are seized. Whats the best way to remove these?

I was thinking drilling them out but I don't want to risk damaging the threads if I can help it. Any other methods? If not, how much would an LBS charge to get them out?

Cheers,

Tom

Something like this?

http://www.screwfix.com/p/screw-extractor-5-piece-set/18643

Have used to remove rounded off bolts with success before

Well, this looks perfect. Just ordered some to collect. I'll let you know how I get on. Cheers mate.

Hammer in a torx bit.

tried both of these suggestions but the grub screws seem like they are monumentally seized

Hmm. I haven't really got any other ideas.. Did you do it by hand or using a power drill?

I used a power drill but it wouldn't bite.

Grub screws can be made of quite hard material and can be very difficult to drill, if possible try starting with something like a 2mm dia drill or less. What size are the grubscrews?
If you can find a grindstone small enough that would probably work with perserverance.

Or buy some super hard bits. https://www.eternaltools.com/carbide-micro-drills

Did you drill a hole in it first? (Just checking!)