I have talked to people who voted for Leave and they now admit that they had no idea what they were voting for. If they had a second vote I think there is no doubt the way it would go - but unfortunately there doesn't seem to be any mechanism to do that.
If there isn't a mechanism to do that, then you need to create your own.
What about giving him ( James Hunt) a call, starting a petition of your own and advertising it via Facebook and Twitter.
Dropping an email to Nicola Sturgeon and the SNP, see if you can get them to add Scotland voters to your petition.
Get as many leave voters together ( create a web page) who now regret it, to put their stories together and publicise it through the media.
Get together have a group on Facebook, have a protest march to number 10.
Make a noise, be heard.
Find out how much support you would get.
Ok you might not succeed, and some of us won't agree in principal with overturning a democratic vote, but again it depends how it is presented and what proportion of leave voters regret it.
No point in getting angry on here.
Once they evoke article 50 it will be to late, because it's not reversible and we would have to reapply with fresh terms.
Which you just know are likely to be crappy to what we have now.