I have used the Gunson's Eezibleed system on a Coupe years ago, I used to use it on my Fiat 124 Spiders, and in fact used an old Fiat 124 Spider brake fluid cap drilled out (a lot of Fiats from the 70's onwards used a standard size of 44 or 45mm IIRC) and it fits the Coupe. As Pete says, you need to drop the pressure on the tyre to something low like 10 psi IIRC. And then when finished, use the pressure with an empty fluid bottle to drive the level down in the reservoir.
But another way is to use a hand-held vacuum "pump" to suck the fluid out at the caliper. You squeeze the trigger several times to create a vacuum (check on the supplied gauge) and hey presto! out the fluid comes. Here's a typical example
but you can pay more. That's my favourite method so far.
You can get other vacuum "pumps" that connect to a compressor, so I assume they act like an ejector to create vacuum, but only any good if you have a compressor.