We've done it ourselves a few times and never had a problem. It's pretty straightforward but be prepared for a bit of elbow grease.

Don't take this the wrong way but after having read what others on here have said about the subject, if you have never cleaned the oven, or hob extract filters whilst living in your apartment then you probably don't have the mindset to do the cleaning to the standard required - or more to the point, to know when you have reached that standard.