As I mentioned on my review, this Rovyvon E300s flashlight was a good candidate for an LED change, due to the tint shift on this light produced by the XP-G3 Leds.
Last friday I received some XP-L Leds ordered from kiriba-ru, and performed that modification.
NOTE: this is not a easy mod, specially for people that have not so good skills - as myself 
- on soldering and opening/closing flashlights. The E300s is somehow complex to open and close without major damages and for some seconds I thought I would lose the most expensive light I have. So, careful if you decide to got for a mod!
There is a rubber “cover” all around the top of the flashlight, to protect from water infiltration. It was hard to get this out and almost worse to get it back to place again!
To access the “pill” and leds, unscrew the top screws on the outside, remove the cover, and unscrew the 3 screws holding the “board”.
To remove the “pill, we have to unscrew the bezel from teh outside. Due to the o-rings and the friction caused by them and the optics, it is very likely that the optics and leds will turn inside. It led my black wire to de-solder so I have to put new wires (22AWG). Thick wires will difficult our life when putting things back together to assemble the light again.
I also broke the black wire coming from the battery while trying to put it together, but it was an easy fix!
The only thing I couldn’t put back together was a sealing ring that was placed between the “pill” and the host (below the bezel). So I improvised and put between the bezel and the host, from the outside. It will work 
About the optic, as you know the XP-L HD leds are taller than XP-G3 and XP-G2, so I had to modify the optic according to this suggestion . It was not difficult but it was hard to make it fit evenly (it can be noticed in the photo). Still, it doesn’t produce artifacts on the beam! 
Las but not least, the beam. Before (XP-G3 CW ) >>>>> After (XP-L V6 3D). During the weekend I will try to take some outdoor beamshots to see the range it will throw!
I can’t portray how “white” it is now, due to the effects produced by the cellphone and the storage loss of quality! Still, it doesn’t have any shift and despite the issues I had modding the optics, it has no artifacts! It is a wider beam now, much floodier than it was, but the XP-L Leds would produce that any way, more than the XP-G3!
I am happy now with this new light colour 