you need to take the rocker cover off , turn engine so exhaust cam at number 4 is at 2 oclock , inlet at 10 oclock, drain oil , jack engine up , remove aux belt and tensioner , remove engine mount ,remove front pulley , all the 6 mm bolts holding the oil pump housing plus one long 8mm bolt , take engine cover off , put rag in bottom of engine so nothing falls in , or you will be taking sump off , remove all 6mm bolts holding guides on, remove tensioner from side of engine 32mm socket, cam sprockets, remove 6mm bolts holding balance shaft guides , and tensioner ,put new crank sprocket on should have a white mark on it ,line up coloured links to balance shafts only can go one way, take your time, fit guides keeping a eye on the crank mark , it will fall off best to wedge it with something, fit all guides , tensioner last , double check all marks line up, if all ok , get a cuppa , fit exhaust sprocket, put new chain in make sure it goes in correctly, theres a big lump in the middle with a little gap, you need to make sure it goes around the back , or its a ball ache to get it around with guides fitted look down from top of engine, line exhaust coloured link to mark on sprocket tie wrap to sprocket , same has inlet tie wrap it to mark so it cant move, put new crank sprocket on wedge it again so coloured link stays in place fit guide inlet side , fit exhaust guide , triple check all links in position , if ok fit tensioner at the back of engine pass the tensioner on a piece of wood to get it to tension it should quite hard to push it into the hole will take a bit of pressure to push it in, don't forget to torque all the 6mm bolts I think its 9-10 newton metres, make sure you pay attention to the crank marks sometimes it looks ok but might be out half a tooth, rebuild all bits back , just try take your time,,