Tell your friend to figure it out himself. It's his 1000 pounds to lose if he wants to take the risk, not yours. It's not that difficult, he can find lots of information online about how to do it. You can even walk him though it step by step and show him which wallet to use, which exchange, etc.
Essentially this is the same as a friend sending you money to buy stocks, another currency, commodity, etc. It's being done on his behalf, so it's perfectly legal. He just should do it himself so he can accept full responsibility for his money.
Rightful thing to be done by a friend not just ordering you to do things which he can actually done without any problems.Its just all the same because you are residing on a same country but be sure on the laws that is connected to crypto before making such any transactions because you might able to face up problems if they would find you out making transactions.
why do you take others risk?
maybe his friend do give out some bonus money for the help that he would do.(possibly)