I don't suppose many people would go through the process of making a complete Landnám set without having tried the game first. Unless you live in Trondheim, Norway (or at least visit here on a Wednesday which is game night at the local gaming club, or the first weekend of November when the annual gaming convention Hexcon is held), chances are that this will be tricky. I know that copies of the game exist in Ukraine, Finland and Canada as well as Oslo, Bergen, Dønna in Norway, but it is unlikely that any of these will be readily available at the moment you decide that you want to try playing the game.
To make it easier to get started, you could print out the components on ordinary paper, and use various pieces from Settlers of Catan and optionally some of its expansions as substitutes for the real thing.
Although Settlers and Landnám both use hexagonal tiles with almost the same terrains, you wouldn't have enough of each kind of tile unless you own several copies of Settlers.
The easiest way is to glue the six edge pieces to a sheet of cardboard approximately 55 by 45 cm (22 by 18 in) and trim away the edges. A mountain hex is glued to the center position as shown in the setup image. As the variable hexes don't move once placed, it is possible to play with paper "tiles" if you tack down a couple of corners with removable tape; if you printed on sufficiently heavy stock, even this might not be necessary.
Alternatively, if you have Cities and Knights of Catan, you could use the edge pieces from this, filling the starting point for the barbarian ship with an ordinary sea tile. The remaining nine sea tiles are used as they are, while all other tiles – regardless of type – are used upside down with the appropriate Landnám design fixed to the back with removable tape as each is discovered.
If you have the 5-6 player expansion or have bought replacement cards, you will have 24 of each kind of resource card, and can use these as long as you remember that bog (marsh) produces iron (ore), mountains do not produce anything and bricks do not exist.
The "fate cards" can be slipped into protective sleeves such as are used for many collectible card games, or printed on heavy stock. If you need to do this for resource cards as well, use a different kind of sleeve or print on yellowish paper so that the two types can be easily distinguished by their backs.
The wooden pieces
The house pieces from Settlers can be used as long as you consider the small (settlement) and large (city) pieces as equivalent, as the distinction between farms and towns in Landnám is made by using either one or two house pieces.
Road pieces can be used as settlers (think "stick men"...) and two roads side by side as boats (think rafts). If you have Seafarers of Catan you do of course use the ships from this.
To be able to play with five players, you will need to have the 5-6 player expansion(s) as well.
As the number counters are moved around quite a bit during the game, it is inconvenient to have these made of paper, even if thicker than normal. But as they are so simple they are easy to make; if you have a stack of blank counters of any shape but of approximately the right size, you can just write the appropriate numbers on them.
Settlers comes with the two six-sided dice required, but you will need to provide two ten-sided dice as well, which are sufficiently different from each other that they can be told apart. Regardless of their actual colour, one of them is designated "green", the other "red".
That leaves just the victory point markers. Just about anything can be used for these, as long as the three types can be told apart. The "red" ones need to be moved around on the board, so if different denominations of coins are chosen, make sure to use the thickest type that is not too wide for this. Note that the actual supply of VP tokens unlike the other components does not limit the availability of what they represent – you always get the victory points you are entitled to.