First of all: it is in fact not possible at this time to sort a stuck payment. The htlcs are a contract in which you agree to fulfill a payment if the routing node provides a preimage within a time window (the timelock). Assume you would be allowed to remove an htlc before the timelock, not only would this be a breach to the contract but it could easily result in a behavior in which you could initiate a payment, the merchant would claim the money, and while the preimage is propagated back to you, you would cancel your htlc causing the routing node to lose money.

Obviously as a protocol extension we could think about making a different onion request "abort routing" which would inform all nodes on the path to abort. This would have to be executed from the recipient back to the sender and would mitigate the above mentioned way of abusive behavior.

However such a new onion request would mean that everyone on the path is responsive to it. If that was the case in the first place the payment would not have been stuck.

It is always hard for mathematicians (like me) to claim something is impossible. But I think in this case we have it by design impossible / undesirable to cancel htlcs from the sender side. (I am happy to be proven wrong and would enjoy a discussion on the lightning dev ml as I think from a UI / UX perspective your request is totally reasonable)

Also keep in mind what removing an htlc currently means. The state of the channel is changed.