The component name is well marked on the circuit board, so you can easily determine where the component should be placed,If you have any questions about Christmas Tree Soldering Kit, A PDF guide can be found at https://attach01.oss-us-west-1.aliyuncs.com/IC/DIY-Manual/7212.pdf 37 PCS Highlight LED: The CTR-30 Audio Flash Christmas Tree Kit Consists of Three Circuit Boards, Allowing 37 PCS Highlight LED to Flash Alternately, Showing A Beautiful Flashing Christmas Tree in A Three-dimensional Outline Space ( Viewing in Night Environment) Power Supply Method: The Working Voltage of the Flashing Christmas Tree Kit Is DC 4V-5V, Which Can Be Directly Powered By 3 AA Batteries Or A USB Power Adapter (with A Battery Holder and USB Cable). Installation Check: If Some LED Lights Do Not Light Up after Welding, Please Make Sure that the Direction and Position of All Components Are Correct. Please Check Whether There Are Some Poor Connections of Solder Joints, Which Is Very Important When Testing. Improve Soldering Skills: The 3D Christmas Tree Soldering Kit Is Designed to Improve the User's Welding Skills. You Will Need A Set of Welding Tools to Complete the Assembly and Welding Process(not Included in the Product), Such as Electric Soldering Iron, Solder Wire, Etc.. The Christmas Tree Welding Kit Can Not Only Be Used For Practice, but also as A Beautiful Christmas Decoration.