corsa b timing help needed

[leem26]

hi i am new here, i have just changed my headgasket and put it all back together and it looks like my timing has slipped so it anyone is clever enough to help me out and help me sort this plz
cheers its a corsa 1.2 8v on a m reg

[cul8tralig8tr]

did you put a mark on the crankshaft pulley and camshaft pulley before you took the head off,also did you mark the outside of the distributor cap.nb in theory you should have turned the crankshaft pulley by hand (after removing battery lead neg)until no 1 piston was at tdc top of compression stroke(rotor arm pointing to no1 cyl plug lead.then mark crank pulley (tipex is easy to see)at top and make a similar mark on cam pulley.for added security you could mark just above crank pulley with tipex on casing the like wise on cam cover.with me so far?

[paterson_uk]

haynes manual have quite a good guide on timing engines