How to make double spending using Bitcoin Core?

1 Shut down Bitcoin Core.
2 Find your Bitcoin Core folder:

Windows XP C:\Documents and Settings\<username>\Application Data\Bitcoin\
Windows Vista, 7, 10 C:\Users\<username>\AppData\Roaming\Bitcoin\
Linux /home/<username>/.bitcoin/
Mac OSX /Users/<username>/Library/Application Support/Bitcoin/

3 Delete the file named mempool.dat.
4 Open or create a text file named bitcoin.conf (.conf extension, no .txt extension).
Add the following line to the file: walletbroadcast=0
5 Now, start Bitcoin Core.
6 You should be able to do Abandon Transaction now. Right-click on old transaction and Abandon.
Bitcoin Core abandon tranaction

7 Create your double spending higher fee transaction.
8 Stop Bitcoin Core.
9 Remove the line you added to the bitcoin.conf file.
10 Restart Bitcoin Core for synchronization and broadcasting.