These instructions are thanks to Moonfire, who wrote them.
Go to the main page, which is http://poserclub.jp/.
You will see an exclaimation point on the left hand side...click the button right underneath that.
In the first box type the user id you want to use.
In the second box type the password you wish to use.
In the third box type your email address.
Leave the last three boxes blank and scroll to the bottom of the page..click the button that is there.
Once you click the button you will be taken to a new page.
Now return to the main page.
Click the download link that is on the top oif the page, with one little man beside it.
To the left up on the site banner you will see English writing that say Poser3D&doll. Click that.
Now down on the left hand side..underneath the exclamation point and where it says join now..you type your user name and password in there and hit enter. (DON'T CLICK ANYTHING!!! Just hit enter)
You will be taken to another page where along the top you will see the download button again..click that.
Now you're at the download page! Go nuts!