Litter training a rabbit

Hi everyone. I have three rabbits. One is 3 years old, another is almost 3 years old and my other is around 7 months old. I'm having an issue. They are outdoor rabbits in well insulated hutches with plenty of hay and straw. My rabbits water runs out fast due to all the hay I give them. I will water them before I go to bed and by the afternoon it'll be gone. Well my yard has short fences and someone has gone into my yard, intruding my property and fed my rabbits lettuce (which I do not like whatsoever! This could have given my rabbits upset stomach) and they also watered them??? I feel so intruded and anyone can see my rabbits are well fed and looked after. Rabbits for one die of dehydration quite quickly so doubt they'd have lasted 3 years and they are overfed by me too cause I love a bit too much, I was told by vet not to feed so much so for someone to come and feed my rabbits is offensive. They are fed a huge helping of food again before I go to bed each night. And if they saw my rabbit in the right hutch they'd have seen a load of food, she tends to not eat as much as the other two so always food left over where as the other two are greedy and will eat really quickly along with all their hay. Anyways after this has happened, I don't feel safe, I don't want anyone approaching my rabbits and ultimately its upset, offended me and my privacy has been completely turned over. This is my home. They have entered my yard. They even left my yard gate open.. What if my rabbits somehow had escaped and they left yard open? They may have thought they were being helpful but I find it uncomfortable and horrible. Alas although I cannot have my rabbits indoor due to being in rented property with new carpets and no space for hutches.. After this incident I want to start bringing them indoors during the day but my concern is obviously the new carpets. How quickly does it take to litter train a rabbit? Does anyone have any advice on how I can help the process? is it possible to have a rabbit wandering my home without stepping in wee left right and centre? I honestly feel so unnerved by this and would rather at least have them in with me part of the day now. Safe in my arms away from anyone who might interfere or even harm them. All my pets are so well loved.. So i am very angry at this gesture. Thanks in advance !

I have now brought them indoors, keeping them in kitchen for now not ideal with cats as had to put their litter trays in the hallway. I just don't feel safe them being outdoors and feel intruded. Any tips of keeping rabbits indoors and managing to successfully litter train them so i can maybe have them in living room with me would be ideal! Cats are fine with them by the way, introduced them all as kittens so they are all loving to each other and have no issues with them being around them

Litter training rabbits is VERY similar to training cats. It doesn't take long as long as you are very diligent about it. Clean up every 'mistake' and put it in the litter box. Watch the rabbit(s) constantly while they are roaming and ALWAYS reward them (with a small treat or tiny bit of green) when they potty in the litter box. Keep in mind, depending on the breed, they may still leave little poops around the house (it's hard for them to control, particularly the tiny guys), but those are quite easy to vacuum. It took me about 4 days to train my male, but he's receptive to all types of training, and I had the week off of classes (I only work part time during the school year), so I was able to watch him the entire time he was out and keep him on track with potty training.