Error CS1525: Unexpected symbol `}'

I downloaded a project for a first person shooter in the internet,and i wanted to change something,but i always get error messages. Help? Here's the code i want to use:

 using UnityEngine;
 using System.Collections;
 
 public class BULLET_ThermalDetonator : MonoBehaviour {
     
     float lifespan = 3.0f;
     
     // Use this for initialization
     void Start () {
     
     }
     
     // Update is called once per frame
     void Update () {
         lifespan -= Time.deltaTime;
         
         if(lifespan <= 0) {
             Explode();
         }
     }
     
     void OnCollisionEnter(Collision collision) {
         
         if(collision.gameObject.tag == "Enemy") {
             collision.gameObject.tag = "Untagged" ;
             Destroy(gameObject);
             Destroy(collision.gameObject.tag = "Enemy")
         } (28th line is here and this phrase is not part of the code,there's only a curly bracket here)
     }
     
     void Explode() {
         
         Destroy(gameObject);
     }
 }
 

This is like,a grenade script. The problem is that in the original one,the grenade hits the target,there's fire and the target won't disappear,and i don't want fire and the target to disappear. I started messing with Unity like,2 days ago and i don't know anything. I would like this to work though. Oh and it says the error is in (28,17),so that means line 28,letter 17? Anyways,it's referring to the first curly bracket below Destroy(collision.gameObject.tag = "Enemy")