Cylinder head leak

[gunrunner]

I have just noticed that the red light has just started to come on more often to find a small oil leak coming from the left front and right rear cylinder head , the oil and filter are due for a change all so .
Is this a gasket change or is it something else .
What do I need to look for ?:ummm:

 

[blaxmax]

Valve cover gasket.

 

[Damon]

check the left upper front & right upper rear intake manifold bolts? They might not have been sealed properly the last time they were re-installed.