Use "Paint" software for this time.
Open the "Paint" software and drag and drop the picture on the canvas.
Click "Size Change"(サイズ変更) and make the width to 960px.
(The main picture of Jimdo is 960px.)
Use "Select tool" to take the part you want to show.
The width and height number is written on the bottom.
Adust the height to 260px and click "Trimming"(トリミング).
You have made the picture of width 960px and height 260px.
Write words by using "Text" tool"(テキストツール). (Set opacity, color, and size.)
Go back to your Jimdo website. Click "Menu"（管理メニュー) on the left menu.
Click "Design" (デザイン).
Click "Custom Tmeplate"（独自レイアウト) on the left menu.
Click "Files"（ファイル) tab.
Change the name of the picture to "visual.jpg". (.jpg is an extention name.) Choose the picture and upload.
Change the part of the alt on line 22.
Fill in the name of the website title.
Sample: You can write "Roppongi Billiard Club" if the website is about billiard club in Roppongi.
(Title is a part that the search engine can read. It does not affect the appearance of the website, but I suggest changing.)
Scroll and click "Save"(保存).
The main picture will appear.