Apple - Open CSV File with Different Separator

In Numbers you can use any separator when importing csv tables.

On the format sidebar, in the table tab, look for adjust Import settings. Inside it you have delimited options where you can even use custom delimiters

Use sed; the Stream EDitor from Terminal.

sed -i -e 's/"|"/|,"/g' filename

s is used to replace the found expression "|" with ","

g is for "global", meaning do this to the whole line. If you omit the g option it will only replace the first instance, ignoring the rest

-i option is to "edit in place" meaning it changes the file itself.

-e option indicates the expression/command to run.