You can follow
this guide to manually remove a transaction from your wallet and double-spend it. Keep in mind that most nodes by default will reject a transaction spending the same inputs even if it pays a higher fee. You are more likely to succeed after a few days when most nodes drop the first transaction from their mempools.
in step:
Press CTRL-F on the keyboard, and search for this hash in the file. It should appear 4 times, in different places, you need to delete them, but carefully to keep the JSON syntax intact, so I have highlighted what you need to delete, it should be different for you, but you will get the idea, it should be everything that is highlighted:
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http://savephoto.ru/f/8yyys3tlxncj19Electrum 4.0.2 for Windows