if you've got the right tools it can be done in an hour. If your not sure,then take your time mate.you will find that the bolts/screws you take out are all slightly different and therefore easy to remember where they go. THERES NO WAY I WOULD WELD IT IN TWO PLACES
if you melt it you will have major probs.ie if you get another loom,then most have been butchered with alarms and sound systems etc etc. WORST OF ALL they could have a wiring fault and youve then got extra probs!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Finally you would probably find it QUICKER to whip the loom out than BODGE IT UP.

DO IT RIGHT FIRST TIME ROUND AND THE PROBLEM WONT COME BACK