I'm using a third party to populate the table (id=roster) contents and almost each tr contains seven th or td (with no id assigned to it). I can't find a good reference or example how to write the removeChild script that can be used to target the multiple non-id assigned sixth and seventh (last child) th or td to remove them.

Also again there's several th without id that has colspan="7" attribute that is needed to be change to colspan"5". I figure I'll use replaceChild with setAttribute but not sure how I should approach the solution. So the question is how should the script be written that'll do the tricks?