WooCommerce Min Max Quantity & Step Control Single plugin offers to set product’s minimum, maximum quantity and step of each product individually. As well as by this plugin you will be able to set the increment or decrement step as much as you want. In a word: Minimum Quantity, Maximum Quantity and Step can be controlled.
Also you can manage the validation of products quantity.
Go to Woocommerce -> Min Max Step Quantity
You will have the option to edit messages.