i had noticed that the jumpers on the olimex-pic gsm is welded on the board does any way to easily change the jumper seetings like J1, J2 ...etc???
It is a decision the routing guys make depending on how often they expect the jumper would be used and whether it is possible to put a PTH type of jumper in the specific location (or board in general). We try to provide all options when possible so we usually end up with a lot of jumpers on the board which confuses some customers but to our mind having more jumpers and never using them is better, than not having all possibilities when needed.
Basic cutting/soldering experience is needed with the SMT jumpers like J1/J2 one of PIC-GSM.