Oiling these notebook fans only 'fixes' them for a short period of time, and most of them are not servicable (oiling) without some serious DIY-ing or drilling a hole in it. I have some experience with these thing. Often the best method is to buy some replacement fan(s) from Amazon or other online retailer and replace the whole thing yourself. In the long run It pays off by not wasting your time oiling them every other month.
Laptop: G751JL
Processor: i7-4750HQ
Graphics Card: GTX 965M
Memory: 8 GB Samsung (stock)
Storage #1: Samsung 850 EVO 250gb
Storage #2: 1 TB 7200 rpm (stock)
OS: Windows 10 x64