I don’t know these engines but aux belts are usually easy to change, on my 4cars they are spring tensioned.
Generally 15mm spanner required, however they are fairly strong springs so need a bit of extra leverage. Take photos of the belt before you take it off as the routing can sometimes be unclear.
However….. I’d be a little bit concerned at this point. On my Volvo D5 engine an aux belt failure can and often does take out the timing belt destroying the engine – but again I don’t know this engine.
And lastly – why has the belt failed? They are usually long lasting. Take the knackered belt off and spin all the driven components by hand – are the idlers/tensioner/water pump all okay? Does this engine have a one way alternator pulley? These need changing but are often missed on service schedules – my V70 pulley seized and shredded the belt in quick order.