How to remove first and last character of a string in SQL Server

Use following code

SET @mykeyword = Substring(@mykeyword, 2, LEN(@mykeyword) - 2)

Lets say, your @mykeyword has "%sheo%", it will return "sheo".

To remove only last character from the string use following code

SET @keyword = Left(@keyword, Len(@keyword)-1)