Grand Theft Auto IV

Get Packies friendship to 75%

Packie enjoies most activities such as bowling and darts and pool and drinking.

Once you have unlocked this ability,call him and then go collect the bomb from the location given ( different places as depends where you are when you call)

EDIT: If I recall right(sold GTA4) Packie will call you whilst you are playing and offer his services after you have reached 75%, so just drive around and continue playing until he calls.

Get Packies Like to 75%

This is what he likes the most:

(From Like to Dislike )

*Drinking
*Gentleman's Club / Strip Club
*Darts
*Bowling/Pool
*Shows

Then you can wait till he calls you and bam! You will get your achievement!

Note: Call Him after 4PM If not he won't answer.

Hope this helps!

To add to the other guides which specify the criteria that should be met in order to get the ability. I haven't seen the following has been mentioned for this achievement, only for the other two, but I'll leave this info here, just in case of any confusion some people might face.

For all of these achievements (get the special ability from a friend) it's also worth mentioning that the achievement unlocks as soon as you get, accept, and listen to the call from the respective friend, and NOT immediately after you achieve the needed percentage of likeness with this friend. In my case for Packie, I was constantly dropping his calls for one or another reason (a car ran over me while I got the call and such accidents), so I had to wait a few days until he finally decided to call once more and finally, I was able to pick up and finish this conversation.

So if you have met the criteria and wondering why you haven't got the achievement, might be that you keep missing or declining these mandatory calls from your friend.