Howto replace a stuck transaction with another with higher fee ?

bitcoind 0.15.0

The marking option "Request Replace-By-Fee" in the sending transaction GUI page should have a better understandable text.

The sender does not "request" anything when creating the transaction. This is just a tag for a later possibility, as I understand as a rather normal user.

I would suggest something like

"Let me increase the fee of this transaction later, if it should not get confirmed in expected time ('Replace-By-Fee' feature)"