Using Perl (sorry: obfuscating code)

perl -pe 's/".*?"/ $& =~ tr[|][]dr /ge'     file

Explanation

• perl -pe proc - apply proc to all the lines
• s/RE/ f($&) /ge - substitutes RE by the result of f(matching string)
• tr[|][]dr - translates | by nothing (=deletes)

Using Perl (sorry: obfuscating code)

perl -pe 's/".*?"/ $& =~ tr[|][]dr /ge'     file

Explanation:

• perl -pe proc - apply proc to all the lines
• s/RE/ f($&) /ge - substitutes RE by the result of f(matching string)
• tr[|][]dr - translates | by nothing (=deletes)