So I found a website that gives out custom lol skins ( I found some pretty cool ones for 
and
) but I recently read around the topic and saw that some players got perma-banned for using them because the program interfered with other files. So basically what i'm asking is, is there a program for custom skin installation that is 100% safe? Or should I stay away from custom skins completely?
First off, here are two very useful threads/posts on the subject: http://boards.na.leagueoflegends.com/en/f/cIfEodbz/d/5kx4F7VE http://boards.na.leagueoflegends.com/en/c/player-behavior-moderation/5dmkJinG-3rd-party-applicationsmodifications-whats-allowed-and-what-isnt
Secondly, the condensed version of Riot's stance regarding custom skins:
For now, custom models and artwork sit firmly in a "use-at-your-own-risk" category, but we're keeping an eye on them. We can't optimize for assets we don't develop, and if they do become a concern in the future (ie. they provide measurable player advantage), we'll take action based on the stance we just discussed.
All that said: Some programs have other features that are not allowed as per Riot's policy. If a program has those features, regardless of whether you use them, that program is not allowed and can get you banned. So either way I recommend you read the OP's of the aforementioned thread to be safe and get an idea what Riot is looking out for. I'd love to also tell you what programs are safe to use, but unfortunately I don't remember the names right now and I certainly don't want to give you a wrong one.
I feel like it entirely depends on the skin and how you got it. If the skin has ANY form of animation or effect that would give you an advantage (usually visually), you could get in trouble. If the distributor isn't safe or the install alters any files, you could get in trouble.
Riot runs a free game and sells cosmetic content to make money, so while they don't have an official stance against custom skins, they do stand firmly on being able to decide if you get banned for them.
