Set valves to Legacy Outback

A warm hello to the Subaru municipality , may I introduce myself briefly to Thomas driving a Lagacy Outback IV 2.5 with LPG , and a Celica . To my problem set the valve play . Was there with the friendly two opinions engine out about 800€ says the one of the other without engine out about . 250€ . Here my Fzg.daten Outback IV 2.5l ( 7106- AAG) Built 12/2007 . I myself have been mechanic this is possible and how are the adjustment data . Thanks for your answers . Greeting Thomas