In general, you buy a fixed asset, depreciate it and then dispose of it when it's at the end of its useful life. All of this is subject to whatever accounting standards an organisation has adopted and is affected by other things such as revaluation, indexation, impairment and replacement, and of course the type of fixed asset that it actually is.
This means that there isn't a comprehensive walkthrough that anybody can provide. You need to refer to the accounting standards you're working with along with the organisation's policies and apply them with regards to whatever the fixed asset is.