Complex sentence: Alton Towers has previously had leases with High Street outlets, which have since been replaced by in-house brands such as Explorers Pizza & Pasta, Fried Chicken Co. and Burger Kitchen.
Split into simpler sentences: Alton Towers has previously had leases with High Street outlets. However, these have since been replaced by in-house brands such as Explorers Pizza & Pasta, Fried Chicken Co. and Burger Kitchen.