Wow... I had no idea it needed to be adjusted by a professional every time... I had had to remove Aidyns carseat literally over 100 times, and always put it back myself... there's no way we could have gone to get it professionally done every one of those times!
I used to always adjust the anchoring strap myself to make sure it was as tight as possible, but then I am pretty confident I was doing it correctly - so if you are unsure then yes, I would go and get it checked by someone. Maybe you can get someone there to teach you how to do it properly yourself?