Would someone tell me how to double spend it in detail I use bitcoin core
#1 remove the existing tx from core
#1.1 close core
#1.2 start core with
-zapwallettxes#1.3 let it do its thing, the TX is gone when its done.
#2 wait 24 hours or longer
#2.1 I said wait 24 hours, dont skip this
#3 issue a new tx.