At right side At left side

Before After
Step1 Go to blogger dashboard then choose template
Step2 Customize > Advanced > Add CSS
paste below code there
.gadget-container:hover,
.gadget-item.ss:hover,
.gadget-item:hover .gadget-container,
.gadget-selected
.gadget-container {right: auto !important;}
#gadget-dock {
-o-transition: left 0.20s ease-in-out 0s;
-moz-transition: left 0.20s ease-in-out 0s;
left: -40px;
-webkit-transition: left 0.20s ease-in-out 0s;
-ms-transition: left 0.20s ease-in-out 0s;
}
#gadget-dock:hover,
#gadget-dock.gadget-notifying,
#gadget-dock.gadget-opening
{
left: 0.5px !important;
}
.gadget-container {
-moz-transition: left 0.20s ease-in-out 0s, opacity 0.20s ease-in-out 0s !important;
-webkit-transition: left 0.20s ease-in-out 0s, opacity 0.20s ease-in-out 0s !important;
-ms-transition: left 0.20s ease-in-out 0s, opacity 0.20s ease-in-out 0s !important;
-o-transition: left 0.20s ease-in-out 0s, opacity 0.20s ease-in-out 0s !important;
left: 0px !important;
right: -100px !important;
margin-right: 100% !important;
}
Apply to blog and then visit your blog and check it is working fine.Enjoy customize dynamic menu.