Items needed:
-Red Chinchompa's (Ranged 85-99 is 50-60k chimp)
-ALOT of prayer pots
-Good gear
-A few other small things like sharks, super anti's, etc.
-Gree gree (optional) (I think one prayer potion is better, just start melee praying when you enter the tunnel and you have 2 dose left when you are at the spot.)
-Holy wrench (optional)
BEFORE you start buying those items, you need to make a choice:
-Training without range boost prayer which means you need more chinchompa's and time but less prayer potions (this is the cheapest way).
OR
-Using ranged boost prayer and buy less chinchompa's, but you will need more prayer pots (this way is faster but also more expensive).
I prefer using Hawk eye boost prayer, you will hit good, and it won't cost much more.
-About The Skeletons (Monkey's)
You are fighting Skeletons , those undead lvl 142's have 112 hitpoints, give 113 Slayer xp and drop nothing.
How do I make them agressive again?
Run till your location is off the minimap. Run back and the monkeys will be agressive again. After about 1.5 hour, they won't get agressive again unless you run out the tunnel.
Note: when running, watch out for the traps!
- Time/Xp table
This is the xp an hour if you pot when your range pot drained 4-5 ranged level's.
85 = 120-130k xp each hour
86 = 120-130k xp each hour
87 = 120-140k xp each hour
88 = 130-150k xp each hour
89 = 140-160k xp each hour
90 = 150-170k xp each hour
91 = 155-175k xp each hour
92 = 160-180k xp each hour
93 = 165-195k xp each hour
94 = 170-200k xp each hour
95 = 175-205k xp each hour
96 = 180-210k xp each hour
97 = 190-220k xp each hour
98 = 200-230k xp each hour
99 = 210-240k xp each hour
With hawk or eagle prayer it'll be even more (up to 300k xp each hour).