Do yourself a favor and drain the engine oil. Look for any bits of plastic rails, both in the drain pan and in the oil pan with a flash light. If your chain has been loose for a while, its probably managed to break the plastic chain guides. They get brittle over time.
IF your lucky and you find no pieces, you can proceed with a simple swap of the chain. The long plastic guide they sent you is pressed by the tensioner against the chain.
IF you find pieces............prepare for some serious work. You will have to dismantle the front cover and oil pan to replace all the guides. It is the biggest pain in the arss!!!!!!!!! THE ABSOLUTE worst car I have ever worked on!! If those guides are broken, it means the chain is rubbing against the metal pins that support the guides. When these get cut through by the chain, they could get injested by the oil pump and cause engine failure. Broken chain rail!!!!
I ve been there and replaced mine.
You don`t need a special tool to crimp the new chain. You can simply use a punch and or a ball pin hammer to lock the link.