Installing LMS on my new DS420+

Hi to all,

I've been using LMS for quite a long time on 2 Synology Nas - DS211 & DS508 -without problems with 2 Logitech Radios

LMS is still running on my DS508 : 7.7.2-006

Question is it possible to install LMS on my DS420+ and eventually upgrade my DS5085 to the latest available open package ?
I read many threads but I got confused with the amount of info and also as they all appeared to be posted quite some time ago :)

What's the latest and where to find it ?
I'll be much grateful if someone could point me to the right starting point!!

Many thanks