Antenna cable replacement

[edmundopt]

hi
 ok, so I went to replace my electrical  antenna interior, at the time I cut the antenna cable, then I found out that the inner wire is very hard to solder with tin.
 to solve the issue, I crimped two SMA , however it didn't last long.
 I am going to replace all the antenna cable, for one with cooper inner wire, but before I do that, has anyone replaced it?

 how hard will it be to replace that connection ?
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