how do you change oil to an automatic gearbox on the ford focus zetec 1.6

I checked my oil levels after some time and found them to be low I was also
experiencing gear change problems  this being an automatic gear box the garage
told me to add oil to the gear box but did not tell me where? whoops  I cannot
find another oil filler point on the engine ? also the orange light is on when it get
warmed up after abut half a mile or so then it seems to bump into gear .

Thank you  fine