If you use Chrome browser it will auto translate the web page, if not just copy/paste the txt into google translate.
If the shop ships international, you can usually just click and buy, if you're struggling with the check out process, just email the shop and ask them to send you a PP invoice for the goods +UK shipping.. don't forget to give them your shipping address.
If they don't ship international then you'll have to use a proxy / buying service like ZenMarket or fromJapan.. it makes no difference if it's a bricks n' mortar store or a bidding sie, it's the exact same process.
Both Circles in Nagoya, Blue Lug and Amazon JP keep a large inventory, UK shipping is easy via either of these sites so if you can find your item here it will make life a lot easier.. if it's a niche item, then follow the advice above^