What tool is used to remove screws for low profile cards



I'm not exactly too sure what you mean, but i wish to be able to remove the screws holding the brackets togther, as i want to install a low profile card.
 
The nuts are 5mm.
Standard Phillips sizes for PCs are #1 and #0.
Then you start seeing #00 and #000 for laptops, cellphones, and the other really tiny screws.

You need a PC toolkit to get the 5mm nut driver for those screws, now you can always just use a pair of pliers.
B&Q does not make pc specific tools, just house tools from what I can see on diy.com under their tools. Why do you specifically need tools from them?
This will do everything you need for generic desktop work: http://www.amazon.co.uk/367/dp/B0001NYK66/ref=sr_1_4?ie=UTF8&qid=1437076398&sr=8-4&keywords=pc+tool+kit


EDITED: The standoffs are 3/16" size which is .1875 inches or 4.8 mm, a 5mm nut driver would work without any issues
 


Mostly because i live in the UK and don't want to wait to use my GPU, however B&Q does infact offer 3/16 hex tools:http://www.diy.com/departments/bq-steel-hex-25-piece-hexagon-key-set/174560_BQ.prd

Thank you and Saberus for telling me they ae 3/16 screws, made searching much eaiser.