Thank you for your question.

Here is an Oregon State Extension article about removing your lawn that should be helpful - "When It's Time to Say Goodbye to Lawn, Uproot It First" - https://extension.oregonstate.edu/news/when-its-time-say-goodbye-lawn-uproot-it-first

This article describes an organic method that can be used in the summer and and another method that involves the use of herbicides. With either method, it is also recommended that the sod be removed also as there may still be living grass roots in the sod.