strings.Replace

// :glot
package main

import (
	"fmt"
	"strings"
)

func main() {
	// :show start
	s := "this is string"
	toRemove := " is"

    after := strings.Replace(s, toRemove, "", -1)    
	fmt.Printf("Removed %#v from %#v => %#v\n\n", toRemove, s, after)
	// :show end
}