Have your friend check with usps for weight and size restrictions.
If it's too big or too heavy for usps then your off to fedx or ups.
Perhaps you can split it into two boxes one box going usps the other by a shipper.
You would need to check prices to see what the cost and options are.
I know this might be a bit of an awkward question but do guys recommend any cheap shipping way from US to Ireland. A friend wants to send me some PC Parts for me to finish creating my PC but a lot of the shipping costs a lot . Would you recommend any way to ship like a pc case, video card, psu, ram for a cheaper price . Big thanks.