The "-il" suffix is used for passive voice in Turkish, so "verilmek" means "to be given". Your example is translated as "how to lose 5 kilos (it's the short term of kilogram) in 5 steps" so its also used in "how to" or "what to" phrases. For example: How to build a tent: Çadır nasıl kurulur? (Kurmak: to set, to build; "-ul" suffix implies the "how to" form)