簡単だけどすぐ忘れそう。

package main

import (
    "fmt"
)

func main() {
    t := []string{"0番目","1番目","2番目","3番目","4番目"}
    fmt.Println(t)
    n := 2
    fmt.Printf("%d番目を削除\n", n)
    t = unset(t, n)
    fmt.Println(t)
}

func unset(s []string, i int) []string {
    if i >= len(s) {
        return s
    }
    return append(s[:i], s[i+1:]...)
}

https://play.golang.org/p/53J04UE7dv