I want to use the contingent method, is there any researcher have used it and can give me an idea regarding the methodology and required data for this method.
You are attaching economic value (monetary/non-monetary) for your ecosystems services. There is no definite answer I can tell you to follow specific model. Your objectives and methods you are developing guide your model. In using CVM, some popular econometric models are discrete choice model, logistic regression model and so forth.
Data analysis needs to check consistency (check BLUE) and frame your data on what you want to analyze.
Humankind benefits in a multitude of ways from all kinds of ecosystems: agroecosystemss, forest ecosystems, grassland ecosystems, aquatic ecosystems, natural ecosystems, urban ecosystems, etc. Collectively, these benefits are becoming known as ecosystem services. Ecosystem services are regularly involved in the provisioning of clean drinking water and the decomposition of wastes. While scientists and environmentalists have discussed ecosystem services implicitly for decades, the Millennium Ecosystem Assessment (MA) in the early 2000s popularized the concept.[1] There, ecosystem services are grouped into four broad categories: provisioning, such as the production of food and water; regulating, such as the control of climate and disease; supporting, such as nutrient cycles and crop pollination; and cultural, such as spiritual and recreational benefits. To help inform decision-makers, many ecosystem services are being assigned economic values.