My black sportka 1.6 0& plate

Hi everybody, as a newbe i am a total beginer at this! But i have owned a black sportka fo  3 years now, and have loved the experience! But just lately i have had to fit new plugs,leads, a new injector rail and coil pack,because the warnibg light kept coming on? This seemed to cure the problem, I have also fitted a cone filter and crankcase filter. But today the temp icon lite bright red and started chuging.! I mansged to crawl onto the hard shoulder, after getting the rac out,ha said my gasket had blown!! But not into the engine, where  a white sludge would be be present, so is it an easy job to remove the head??? Hr also said it would be good to chaing the timing chain at the same time! Is this correct? Any ideas about having it done by a garaage!? Thanks a frusrated ka lover

andy