p1.sed
s/\(.*\)\[\(.*\)\]\(.*\)\[\(.*\)\]\(.*\)/\1\
\2\
\3\
\4\
\5/;


p2.sed
1~5h;
2~5 {
    s/:/|/g
    s/^|//
    s/\(.*\)/[\1]/
    H
}
3~5H;
4~5 {
    s/:/|/g
    s/^|//
    s/\(.*\)/[\1]/
    H
}
5~5 { H; x; s/\
//g; p; }


run as:
cat myline | sed -f p1.sed | sed -n -f p2.sed