put the blocks into the asm folder that's included with BTSD and open up BTSD. now follow this
QuoteTag (div) was not closed.Tag (div) was not closed.
1) Click File->Open (or press Ctrl+O) then select your rom.
2) Go to Data->Edit Database
3) This'll be where your blocks will be located so click Add on the bottom right then it'll create a new block
4) If your inserting a bin block, click on the .BIN tab at the top right, if asm block, don't click since it's set to .ASM already
5) fill in the fields by putting in a name for it and a description
6) Now you put in the path to the file. you do not put in the full path like C:\..., you only put it short like asm\block.asm because it's locates it where BTSD is.
IF using asm block, skip this step
7) You do the same thing as before, put in the path, but there is one thing different, it has stuff as the bottom, now usually the block will come with a txt file with the offsets of what you put. if it doesn't then if it's for sprites, you put in 0 for SpriteV and SpriteH, if mario, 0 for MarioAbove, MarioBelow, MarioSide, if cape, 0 for MarioCape, if fireball, 0 for MarioFireball. Now some blocks will require Relocs but it's barely been used in the blocks submitted to the site.
8) Now that you have that done, go to Block->Insert (or press the Insert button)
9) now here will be your blocks, click on the one you want inserted and on the bottom will be what Map16 tile it will be. put in a Map16 number and then press ok
10) Save and if you'd want to, you can test it to see if it works or not.
I change my layout every 4-5 months