"Hi, how might I worship Khronos, the god of time?"
Contrary to the Olympians, the pre-Olympians are actually of the world; They, together, form the tapestry of earth and life. They literally make up our universe. The Protogenoi (Πρωτογενοι) are the First Born Deities of the Hellenic Kosmos. They are the building blocks of the universe, primordial Deities. Khronos--in some genealogies--is one of them.
Khronos is often confused with Kronos; father of Zeus and considered a harvest God for his link to the Golden Age. Khronos, however, is the creator of the Gods and Lord of Time. Kronos is outdated by Khronos by a few generations. In the Orphic cosmogony, Khronos was alone in the void. He created both Aether and Chaos who produced the Primordial Egg from with the hermaphroditic Theos Protogonos emerged. From Him, Ouranos was born, making Khronos, Kronos' great-grandfather. They are neither the same God, nor do they rule over the same domains. Most of the confusion comes from the Roman deity of Saturn, who is a harvest God, Father Time and the father of Jupiter--Zeus' equivalent--combined.
Not many Hellenes regularly worship the older Gods these days. They didn't in ancient times either. Yet, the Olympians did not come to power in a vacuum, and I think to banish all who came before from your worldview and religious life is a disservice not to just the Protogenoi and Titanes, but the Olympians as well. The Old Gods are just as Deathless, just as present, as the Olympians. They are more passive, surely, than the Olympians, but no less worthy of honour for making this world such a beautiful place to live in. They (generally) don't have festivals, and They receive less honour than the Olympians, but they are worth honouring none the less.
There is no fixed ritual format for the worship of Protogenoi and other deities older than the Olympians. Mostly, when they did receive worship, they would have received it in the regular way: procession, purification, prayers and hymns, sacrifice/offerings, prayers of supplication and thanks, usually followed by a feast and/or theatre and sporting events. The same would go for Khronos. and today? Well, how do you give modern sacrifice to the Theoi in your own home practice? Apply that to Him as well. As I have said before, Hellenismos is wonderfully boring when it comes to worship: repetition, repetition, repetition. Beautiful devotion in its purest form.