Sprint Sprint Rs Front Wheel Removal. Tool?

Hi all, I recently bought another Sprint RS to use as a donor and, today I was going to change the wheels over as my rear tyre was worn out but the donor has almost new tyres. A bit of wrestling and I got the rear tyres swapped over but I then went to look at the front end and was confronted by this huge hex/allen head. Not got any keys that big. Any ideas on something I can use in place of the correct tool or a workaround for the moment?

 

Thanks @Duckadiledundee I have ordered the correct tool (a stepped hex jobbie for various axles) and, hopefully it will be here Saturday or Monday but I want to go out now!!! Well not right now but soon. It's been drizzly/rainy ever since this afternoon. That fine stuff that coats your visor and blinds you unless you get up to around 110mph where it bounces off but, unfortunately those sort of speeds don't feel too safe in the wet. The tyre on the front is OK but it's a totally different pattern so not sure how the two would work together. Front is a Michelin Pilot road 2 where the tyre on the back is now a Pirelli Angel ST.

 

Got my 'Motorcycle Spindle tool' on Saturday morning and got straight down to swapping the front wheels over. Once it was done I took the old girl for a spin. Jeez what a difference! I don't know if it was my imagination but when I was still on the old Michelin Pilot Road 2's, even when they had a legal amount of tread, I felt as if the rear wheel sometimes wanted to come out from under in tight corners even at very moderate speeds and I just didn't feel that well planted on the road but, from the minute I rolled out on the Pirelli Angels the bike felt like a different animal. I simply didn't get the feeling I had had previously that she wasn't stuck firmly to the road in the twisties and I was going much farther over and much faster without even the slightest sense of insecurity. I am wondering if the old tyres (Am I right in thinking that Michelin Pilot Road 2's are quite an old tyre?) had somehow gone off or simply weren't that good in the first place.